A video sent by NYPD officers to the NYCLU through its app that looks to document "stop-and-frisk" practices.

It's easy to use: One tap starts recording, then you shake it to stop. Enter information about what you saw and where, and hit send. The NYCLU reviews every video and report it receives and investigates all submissions representing misconduct to the fullest extent possible. There's an alert system telling you if other app users are recording nearby.

Since the Android version launched last June, users have submitted 200 videos documenting police incidents. With the iPhone version, the NYCLU expects those numbers to increase.

"While we've yet to see a 'Rodney King' moment, Stop and Frisk Watch submissions have confirmed a number of concerns the NYCLU has about stop-and-frisk abuse and has provided New Yorkers with a powerful tool to document police abuse," announced Donna Lieberman, head of the NYCLU. "We're proud that the app is used every day in New York City and that the attention it has received has encouraged people to document and expose police activity with their smart phones."

"Stop and frisk," a controversial NYPD practice of stopping young men — nearly always men, and nearly always minorities — and frisking them on the street in public has been highly controversial. In 2011, NYPD stopped and questioned people 685,724 times. Nine out of ten of those stopped were innocent, and 87% were black or Latino.

The NYCLU received 5,000 video recordings, the majority of which were users trying to test the app. The new version includes a how-to video to alleviate that problem. "But that's a good problem to have," NYCLU told BuzzFeed. "It's wonderful to know that more than 5,000 people were so focused on the issue and so excited to get involved that they were testing the app and seeing how it works."

Despite the low number of actual police incidents recorded, the NYCLU has received numerous requests from other groups, including ACLU affiliates, who want to create similar apps of their own.

Proponents of recording police actions on video, like Joseph Hayden of All Things Harlem, claim they've successfully changed the way the NYPD operates. Hayden has been posting videos of stop-and-frisk-related police misconduct since 2008 on his website, which was originally a community news outlet. It's now a leading source of Cop Watch videos.

"The NYPD routinely looks at our videos and responds on YouTube and Facebook," says Hayden. "It has reached such a point now that they know they are under the microscope and that has had a tremendous impact."